/**
 * Created by zhangxiaoyu on 2017/6/23.
 */
//2011-7-25
(function(){        //闭包
  function load_script(xyUrl, callback){
    var head = document.getElementsByTagName('head')[0];
    var script = document.createElement('script');
    script.type = 'text/javascript';
    script.src = xyUrl;
    //借鉴了jQuery的script跨域方法
    script.onload = script.onreadystatechange = function(){
      if((!this.readyState || this.readyState === "loaded" || this.readyState === "complete")){
        callback && callback();
        // Handle memory leak in IE
        script.onload = script.onreadystatechange = null;
        if ( head && script.parentNode ) {
          head.removeChild( script );
        }
      }
    };
    // Use insertBefore instead of appendChild  to circumvent an IE6 bug.
    head.insertBefore( script, head.firstChild );
  }
  function translate(point,type,callback){
    var callbackName = 'cbk_' + Math.round(Math.random() * 10000);    //随机函数名
    var xyUrl = "http://api.map.baidu.com/ag/coord/convert?from="+ type + "&to=4&x=" + point.lng + "&y=" + point.lat + "&callback=BMap.Convertor." + callbackName;
    //动态创建script标签
    load_script(xyUrl);
    BMap.Convertor[callbackName] = function(xyResult){
      delete BMap.Convertor[callbackName];    //调用完需要删除改函数
      var point = new BMap.Point(xyResult.x, xyResult.y);
      callback && callback(point);
    }
  }

  window.BMap = window.BMap || {};
  BMap.Convertor = {};
  BMap.Convertor.translate = translate;
})();
